The present invention relates generally to a push-pull exercise apparatus, and more particularly to a partial turn exercise wheel having a cam outer surface and asymmetric gravitational energy storage and return.
Various roller devices have been designed to provide kneel-prone-kneel exercise. These devices, when employing assisted return to the kneeling position, may be characterized as spring, cam, or inclined plane types. Among the spring types are those described in U.S. Pat. No. 2,821,394 to Barbeau, U.S. Pat. No. 3,708,164 to Griffin, U.S. Pat. No. 3,752,475 to Ott, U.S. Pat. No. 5,707,325 to Chiou, U.S. Pat. No. 6,174,269 to Eschenbach, and U.S. Pat. No. 6,017,296 to Tang et al.
In U.S. Pat. No. 5,707,325, Ott describes the use of a cam in conjunction with a spring. As there is no irrotational stroke segments, the periphery of the cam must be at least equal the length of the longest stroke desired, resulting in greatly reduced workout effectiveness, as the rotational axis of the cam must then be elevated excessively to accommodate a circumference equal to or greater than the maximum desired stroke. An inclined plane type is described in U.S. Pat. No. 5,921,901 to Palaclos, who also adds an elbow rest trolley to the trolley/track kneel-prone-kneel method. None of the aforementioned patents discloses a combination of cam and roller or slider action to achieve asymmetric energy return.
The present invention provides a compact push-pull exercise apparatus having a partial turn outer cam surface in contact with a random surface such as a floor, and one or more handles rotatably mounted to the cam rotational axis. The operator begins an exercise cycle in the kneeling position with hands on the handles and with arms generally near the vertical position. The operator pushes the apparatus forward to a stopping position with the operator nearly prone. During the first portion of the forward movement, gravitational energy is stored as the cam rotational axis is lifted. During subsequent forward motion, the vertical displacement of the rotational axis from the random surface is unchanged. As the operator reverses the movement from the prone position to the kneeling position, gravitational energy is released during the first portion of the in-stroke to ease the return motion during the most difficult portion of the exercise cycle.
It is an object of the present invention, therefore, to provide a push-pull cam action exercise apparatus for use with a random surface.
It is another object of the invention to provide a cam action exercise apparatus having asymmetric energy management.
It is another object of the invention to provide a cam action exercise apparatus for use with a random surface having a rotational axis close to the random surface.
It is another object of at least one embodiment of the invention to provide a wheel for employment by an operator on a random surface, whereby abdominal and other muscle groups of the operator are effectively exercised by a repetitive kneel-prone-kneel routine, in which energy is absorbed during the first portion of the kneel-prone out-stroke, and returned during the first portion of the prone-kneel in-stroke.
It is another object of at least one embodiment of the invention to provide a cam action exercise apparatus having an out-stroke with a translation/rotation first portion and a translation/irrotation second portion, and an in-stroke with a translation/rotation first portion and a translation/irrotation second portion.
It is another object of at least one embodiment of the invention to provide a method of abdominal exercise for a operator, wherein gravitational energy is stored by vertical displacement of a cam axis during the first portion of the out-stroke of a kneel-prone-kneel exercise routine, and returned during the first portion of the in-stroke, and wherein substantially no gravitational energy is either stored or returned during the remainder of the exercise cycle.